Determination of paraquat in raw and formalin-fixed tissues by electron spin resonance (ESR) spectroscopy

ESR method was applied to determine paraquat levels in fresh and formalin-fixed tissues. Paraquat was converted to paraquat radical by adding sodium dithionite to tissue homogenates and detected by ESR. Paraquat levels of more than 0.2 micrograms/ml homogenate could be quantified with 0.1 ml of the homogenate. The use of manganese ions for standardization of paraquat signal enabled much more accurate ESR measurements because this ion was quite stable and its signal did not overlap that of paraquat. Even with tissues fixed in formalin, tissues paraquat levels were measureable after removing formalin from the tissue extract. This fact was verified by studying two cases; the tissues were kept in formalin for 1.5 years in case 1 and for 6.5 years in case 2. In both cases, the paraquat contents in tissues were 0.02-0.08 micrograms/g. In this way ESR is one of the most suitable methods in determining low levels of paraquat in tissues even after they were preserved in formalin for a long time.     

Quantitative analysis of chlorpromazine by electron spin resonance (ESR) spectroscopy

A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 μl of the solution containing 0.5 μg chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample.     

Quantitative analysis of chlorpromazine by electron spin resonance (ESR) spectroscopy.

A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 microliters of the solution containing 0.5 microgram chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample.     

Extraction of diquat with 1-butanol from biological materials

Diquat can be extracted with 1-butanol from high pH solution in the presence of several moderate reductants. The red colored reduced compound of diquat in water turns to a purple compound in 1-butanol. The absorption of the purple compound is 0.105 at 383 nm and 0.119 at 520 nm in 1 microgram diquat/ml 1-butanol. The latter value is a little higher than that of the red compound at 495 nm in water. The purple compound is much more stable than the red compound in water. More than 80% of 10 ppm diquat added can be extracted from serum, blood, tissues, urine and some drinks. The extraction with 1-butanol is useful for concentration of diquat contained in large volume. The lower limit of detection is 0.1 microgram/ml 1-butanol. Paraquat is insoluble in 1-butanol under the same condition. Therefore, this method is applicable for the determination of diquat when paraquat is also contained in the solution.     

紫外分光光度法检测尿中敌草快

目的为尿液中敌草快的测定研究一种简单可靠的检测方法。方法将尿样高速离心,上清液转移至试管中,加入不同的碱性溶液调节p H,加入连二亚硫酸钠显色,于378nm比色测定。结果敌草快在0.1-10μg/m L呈良好线性,相关系数为0.998 8,回归直线方程Y=0.114 9X＋0.010 3。最低检出限为0.02μg/m L,日间和日内精密度分别为4.50%,6.28%。结论此方法操作简便、快速,适用于临床监测和法医毒物分析。     

紫外分光光度法和二阶导数光谱法测定水样中的敌草快

目的建立测定水样中的敌草快的分析方法。方法采用紫外分光光度法和二阶导数光谱法测定水样中的敌草快。结果紫外分光光度法直接测定水样中的敌草快,在0.1~50μg/mL范围内线性关系良好,日内,日间精密度均小于2.6%。二阶导数光谱法在0.1~10μg/mL线性关系良好,日内、日间精密度均小于1.29%。结论该两种方法快速、简单、灵敏,适用于环境监测工作。     

Determination of glyphosate in biological fluids by 1H and 31P NMR spectroscopy

Identification of glyphosate in four cases of poisoning, using nuclear magnetic resonance spectroscopy of biological fluids is reported. It has been performed by using a combination of 1H and 31P NMR analyses. Characterization of the N-(phosphonomethyl) glycine herbicide was achieved by chemical shift considerations and coupling constant patterns: CH2-(P) presents specific resonance at 3.12 ppm and appears as a doublet with a H-P characteristic coupling constant of 12.3 Hz. Moreover, resonances due to isopropylamine were present, confirming the ingestion of the considered trade formulation. After a calibration step, quantitation was performed by 1H and 31P NMR spectroscopy. The benefit and reliability of NMR investigations of biological fluids are discussed, particularly when the clinical picture is quite confusing.     

Quantification of propane in biological materials by head-space GC

Propane was measured in specimens taken from two persons who died from a LPG explosion in an apartment using head-space-GC/FID. Because of the variation of instrument performance and sample injection, the internal standard pentane was used. Calibration standards were prepared by injecting each calculated volume of pure propane gas into capped vials containing 2 ml of blood and 5 microl of internal standard. The calibration curve revealed good linearity from 0.09 microg/ml to at least 90 microg/ml. The method validation data also included repeatability and recovery. The propane quantities in blood, fat and brain tissue were between 0.27 and 71 microg/ml (microg/g) with the highest concentration observed in fat. The confirmation of propane was conducted by the means of solid phase micro-extraction and mass spectrometry.     

Toxicological analysis of lidocaine in biological materials by using HPLC

A rapid and reliable method to analyze lidocaine in biological materials was developed using column extraction method and high performance liquid chromatography (HPLC). Two peaks for lidocaine and procaine as an internal standard (IS) were separated clearly with no interfering peaks appearing in the chromatogram. The annual change of lidocaine caused intoxications was described. From medico-legal aspects, the method was applied to authentic samples from autopsied victims and concentrations of lidocaine in 29 cases were evaluated briefly.     

生物检材中乌头碱的LC-MS/MS快速分析

目的应用高效液相色谱-质谱法对生物检材中乌头生物碱等有毒成分进行快速分析。方法取全血样品经乙腈-甲醇(5:1 v/v)提取,使用Agilent Zorbax SB C18(2.1 mm×50 mm,1.8μm)色谱柱,以0.1%甲酸溶液-乙腈(60:40 v/v)为流动相等度洗脱。在多反应监测模式下测定全血样品中乌头生物碱等有毒成分。结果乌头碱、次乌头碱和中乌头碱的保留时间为0.73 min、0.77 min和0.63 min;用于定量分析的离子对分别为m/z 646.4→586.4(乌头碱)、616.1→556.5(次乌头碱)和632.4→572.1(中乌头碱)。乌头碱在0.1~250 ng/m L内线性关系良好,相关系数(r)≥0.9987,最低检出限0.1ng/m L,精密度考查其变异系数(CV)5.42%(n=6),血液中乌头碱提取回收率不小于90%。结论本文建立的高效液相色谱-质谱法快速、简便、灵敏,适用于天然药毒物检验。     

Determination of 2.4-dinitrophenol,its basic metabolite and 4-oxide diphenyl in biological materials

A possibility was considered to isolate, by using dimethylformamide, 2.4-dinitrophenol, 2-amino-4-nitrophenol and 4-oxid-diphenyl from a biological-origin object. A method of extraction with subsequent chromatography in thin silicon-gel layer was used to purify the isolates from biological materials. The designed technique provides for identifying and for quantitatively defining the discussed phenol structures contained in the isolates from the liver tissue of corpses and human blood.     

Estimation of the age of human bloodstains by electron paramagnetic resonance spectroscopy: long-term controlled experiment on the effects of environmental factors

In this study, we examined the efficacy and limitations of electron paramagnetic resonance (EPR) for estimating the age of human bloodstains. At 77K, human bloodstains give four striking EPR signals in the g=6.2 (g6), 4.3 (g4), 2.27 (H) and 2.005 (R) regions due to ferric high-spin, ferric non-heme, ferric low-spin and free radical species, respectively. We found that plotting double logarithms of the EPR intensity ratio of H/g4 versus days past bleeding gave a linear correlation up to 432 days with an error range within 25% of the actual number of days under controlled conditions. However, environmental factors such as differences of absorbent, light exposure and fluctuations of storage temperature affected the changes of these EPR-active compounds, which result in misestimation of the time since bleeding occurred. Therefore, one should take such factors into account in estimating the period since bleeding by this method.     

The detection of nifedipine in biological materials

The objective of the present study was to find optimal conditions for the isolation of nifedipine from biological materials by ethylacetate. It was shown that nifedipine can be purified from co-extracted substances of the biological material on a Silasorb C-18 column with the size of the particles 30 microns. The authors propose to use thin-layer chromatography, IR spectrophotometry, and reverse-phase high performance liquid chromatography for the identification and quantitative determination of nifedipine extracted from cadaveric liver samples.     

Colorimetric determination of endrin in biological materials

A simple colorimetric method for the determination of endrin in formulations has been reported. In the present communication, the application of the method to biological specimens is discussed. The method is sensitive and obeys Beer's law for the concentration range 4 – 40 μg/ml, with 99 ± 3% recovery of endrin added (in vitro) to the biological specimen.     

GC/MS法测定人体血液和肾、肝组织中的丙泊酚

目的 采用气相色谱/质谱法检测人体血液和肾、肝组织中的丙泊酚.方法 心血和肾、肝组织中的丙泊酚经环己烷提取,采用气相色谱/质谱法,丙泊酚选择m/z 163、178,内标百里香酚选择m/z 150、135进行测定;并考察方法专属性、线性范围、定量线与检出限、回收率与精密度.结果 丙泊酚的保留时间为8.17min,与内标百里香酚分离良好;其在心血和肾、肝组织中的检测浓度线性关系良好,r值均大于0.992,最低检测质量浓度分别为0.05 μg/mL、0.10μg/g及0.05 μg/g,方法回收率90％ ～ 110％,日内、日间RSD均小于7％.结论 本文方法简便、灵敏、快速,其准确度、精密度和回收率均可满足生物检材中丙泊酚浓度的测定,可在相关研究及实践中选用.